Global Patent Index - EP 1143602 A3

EP 1143602 A3 20031126 - Active filter for reduction of common mode current

Title (en)

Active filter for reduction of common mode current

Title (de)

Aktives Filter zur Gleichtaktstromreduzierung

Title (fr)

Filtre actif pour réduire le courant de mode commun

Publication

EP 1143602 A3 20031126 (EN)

Application

EP 01107921 A 20010328

Priority

  • US 19297600 P 20000328
  • US 21199900 P 20000616
  • US 81659001 A 20010323

Abstract (en)

[origin: EP1143602A2] An active filter reduces the common mode current in the ground wire of a PWM controlled motor drive circuit. The active filter is, in part, integrated into an integrated circuit chip and contains a buffer amplifier which drives two junction type or MOSFET transistors linearly to divert common mode current from a ground wire and through the transistors. The transistors are connected between positive and negative d-c busses which supply d-c power to a PWM inventor which drives an a-c motor, producing the common mode ground current in its grounded frame. A current transformer monitors the common mode current and its output is coupled to the input of the buffer amplifier to control the transistors. An internal power supply for the amplifiers is formed at the nodes between two current sources and two zener diodes which are connected between the d-c bus conductors. Headroom control circuits are disclosed to insure sufficient headroom voltage for each of the transistors under all input a-c voltage conditions. <IMAGE>

IPC 1-7

H02M 1/12

IPC 8 full level

H02M 1/12 (2006.01); H02M 5/458 (2006.01)

CPC (source: EP US)

H02M 1/12 (2013.01 - EP US); H02M 5/458 (2013.01 - EP US); H02P 29/50 (2016.02 - EP US); H02M 1/123 (2021.05 - EP US); H02P 2201/07 (2013.01 - EP US)

Citation (search report)

Designated contracting state (EPC)

AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR

DOCDB simple family (publication)

EP 1143602 A2 20011010; EP 1143602 A3 20031126; JP 2002010650 A 20020111; JP 3428588 B2 20030722; TW 512574 B 20021201; US 2001045863 A1 20011129; US 2004004514 A1 20040108; US 2004207463 A1 20041021; US 2007120607 A1 20070531; US 2008180164 A1 20080731; US 6636107 B2 20031021; US 6794929 B2 20040921; US 7187229 B2 20070306; US 7385438 B2 20080610; US 7583136 B2 20090901

DOCDB simple family (application)

EP 01107921 A 20010328; JP 2001092990 A 20010328; TW 90107255 A 20010327; US 5598208 A 20080326; US 60927303 A 20030626; US 61948107 A 20070103; US 81659001 A 20010323; US 84353804 A 20040510